DUBLIN (AFP) - The run-up to Friday's deadline to seal an international treaty here banning cluster bombs seems set to be dominated by wrangling over helping non-signatories use the lethal weapons. Officials from 109 countries have been in talks at Croke Park stadium in the Irish capital to thrash out a pact that would completely wipe out the use, production, transfer and stockpiling of cluster munitions among signatories. The process, started by Norway in February 2007, has sidestepped the United Nations to seal a swift pact. And in the final few days to strike a deal, campaigners face a fight to get the draft language on inter-operability, or knowingly assisting other states to use cluster munitions, changed to rule out doing so. That will be the key concern in the remaining days, said Thomas Nash, coordinator of the Cluster Munition Coalition (CMC), an umbrella group of non-governmental organisations. "We're much further ahead than we thought we would be after the first week and we're certainly much closer to agreement on the definition of cluster bombs," he told AFP. "But what's on the table now would allow assisting countries that don't sign up with the use of cluster munitions. That's hugely disturbing. "We don't see how the treaty could be credible if this language is retained. It would fundamentally undermine the humanitarian purposes of the treaty." Nash singled out Britain, saying it would become increasingly marginalised if it was not willing to agree banning intentional assistance in using cluster munitions. "(Prime Minister) Gordon Brown needs to decide whether he wants the relationship with the United States to stand in the way of a major milestone in humanitarian protection," he said. "This is a chance to stigmatise the weapon and prevent it from being used. "The idea that we face up to the reality that it is going to be used is not the right approach." He said the other two issues to resolve were: defining which weapons are considered cluster munitions; and deciding whether there would be a transition period in which they could still be used. "It's going to be a balance and everyone's going to have to give something," Nash said. Notably absent from the conference - even in an observer capacity - are China, India, Israel, Pakistan, Russia and the United States - all major producers and stockpilers.